Geriatric emergency department revisits after discharge with Potentially Inappropriate Medications: A retrospective cohort study

Objective: To determine whether Potentially Inappropriate Medications (PIMs) prescribed in an academic emergency department (ED) are associated with increased ED revisits in older adults. Methods: A retrospective chart review of Medicare beneficiaries 65 years and older, discharged from an academic ED (January 2012 – November 2015) with any PIMs versus no PIMs. PIMs were defined using Category 1 of the 2015 Updated Beers criteria. Primary outcomes, obtained from a Medicare database linked to hospital ED subjects, were ED revisits 3 and 30 days from index ED discharge. Adjusted multiple logistic regression was used with entropy balance weighted covariates: Age in years, Gender, Race, Number of discharge medications, Charlson Comorbidity Index (CCI) score, Emergency Severity Index scores (ESI), Chief Complaint, Medicaid status, and prior 90 Day ED visits. Results: Over the study period, there were a total of 7,591 Medicare beneficiaries 65+ discharged from the ED with a prescription; 1,383 (18%) received one or more PIMs. ED revisits in 30 days were fewer for the PIMs cohort (12% PIMs vs 16% no PIMs, OR 0.79, 95% CI 0.65 - 0.95, P value <0.005). Hospital admissions in 30 days were fewer for the PIMs cohort (4 PIMs vs 7% no PIMs, OR 0.75, 95% CI 0.56 – 1.00, P value <0.005). In addition to PIMs, covariate risk factors associated with ED revisits in 30 days included comorbidity severity, history of prior ED revisits, chief complaint, and Medicaid status. Risk factors associated with hospitalization in 30 days included those plus age and emergency severity index, but not race nor ethnicity. Conclusions: Patients discharged from the ED receiving potentially inappropriate medications as defined by Category 1 of the 2015 updated Beers criteria had lower odds of revisiting the ED within 30 days of index visit. Sociodemographic factors such as gender and race did not predict ED revisits or hospital admissions. Clinical characteristics predicted ED revisits and hospital admissions, the strongest risk being increasing Charlson Comorbidity Index score followed by triage acuity and chief complaint. Future studies are needed to delineate the implications of our findings.